Liquid-phase hydrogenation of citral over an immobile silica fibre catalyst

A new knitted silica fibre catalyst was introduced into liquid-phase hydrog enation of organic compounds. The fibre catalyst combines the advantages of catalyst slurries and large catalyst particles: diffusional limitations ar e suppressed and the catalyst is immobile, Nickel-impregnated silica fibres were used in the hydrogenation of citral to citronellal and citronellol in a tubular glass reactor where the catalyst was packed in two layers. The l iquid phase was recirculated while the gas phase was flowing concurrently t hrough the reactor to the vent. The highest selectivities to the desired pr oduct, citronellol, exceeded 90%. The catalyst performance was competitive with a conventional crushed nickel catalyst. (C) 2000 Elsevier Science B.V. All rights reserved.